JP3032892B2 - Constant speed traveling equipment for vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a constant speed traveling device for a vehicle for automatically causing a vehicle to travel at a constant speed.

(Conventional technology) As a means for running a vehicle at a constant speed without an accelerator operation on a highway or the like, a vehicle constant speed traveling device as described in, for example, JP-A-60-255534 is conventionally known. I have. This constant-speed traveling device is provided with an actuator for driving an output adjusting means (for example, a throttle valve) of an engine, and controls the actuator in a mode corresponding to various switch operations to adjust a vehicle speed. , A motor or a negative pressure actuator is used. The switch includes a main switch (power switch) for selecting constant-speed traveling, a set switch for setting a target vehicle speed for constant-speed traveling by turning on the switch while the main switch is on during normal traveling, During cruising at a constant speed, for example, when the distance between the vehicles is too large, the driver operates the actuator in acceleration mode by keeping the button pressed to increase the vehicle speed, and sets a new target vehicle speed when released. On the other hand, when the inter-vehicle distance becomes narrow, there is a coast switch that lowers the vehicle speed in a deceleration mode by keeping the driver pressed and sets the vehicle speed at the time of release as a new target value. . Further, the constant-speed traveling device is configured such that, when the brake is depressed or the clutch operation is released during the constant-speed traveling, a cancel mode is set to return to a normal accelerator operation state. After that, a resume switch for returning to the original setting and performing the constant speed traveling is provided.

By the way, in such a constant speed traveling device for a vehicle, if the control gain of the constant speed traveling control is not appropriate, hunting occurs or overshoot or undershoot increases, and stable vehicle speed control cannot be obtained. There was that. Therefore, conventionally, the control gain of the constant-speed traveling device has been adjusted for each vehicle type at the development stage.

However, simply adjusting the control gain for each vehicle type in this way cannot cope with a change in running resistance when the number of occupants or the amount of luggage changes, or a secular change in engine performance. For example, if the gain is smaller than the appropriate value, the time required to return to the target vehicle speed when the vehicle speed drops at a steep slope becomes longer.

(Object of the Invention) The present invention has been made in view of the above problems,
It is an object of the present invention to provide a constant-speed traveling device for a vehicle that can constantly perform constant-speed traveling control with an appropriate control gain in response to a change in the gross weight of a vehicle, a temporal change in engine performance, and the like.

(Constitution of the Invention) The present invention determines whether or not the control gain of the constant-speed traveling device for a vehicle is appropriate based on the number of changes of the sign of the differential value of the vehicle speed deviation with respect to the target vehicle speed (this sign is called an acceleration sign). Thus, the control gain can be automatically adjusted to an appropriate value during traveling, and the configuration is as shown in FIG. That is, the vehicle constant speed traveling device according to the present invention sets the engine output adjusting means for adjusting the output of the engine, the actuator for driving the engine output adjusting means, and the target vehicle speed of the vehicle driven by the engine. Target vehicle speed setting means, vehicle speed detecting means for detecting an actual vehicle speed, and constant speed traveling control means for controlling an actuator based on a deviation between the detected vehicle speed and the target vehicle speed to maintain the vehicle in a constant speed traveling state. An acceleration code detecting means for detecting an acceleration code from a vehicle speed change state during a constant speed driving control, and receiving the output of the acceleration code detecting means and receiving the output of the acceleration code detecting means, A control gain changing means for changing the control gain of the constant speed traveling control means so that the number of times becomes a predetermined number.

(Operation) The constant speed traveling control means controls the actuator based on the deviation between the actual vehicle speed and the target vehicle speed. Then, the engine output adjusting means is driven by the actuator, and the vehicle is maintained in a constant speed running state. At this time, it is determined how many times the acceleration code has changed within a predetermined time, and the gain of the constant-speed traveling control means is changed so that the number of changes becomes a predetermined number. In this way, the control gain is automatically adjusted to an appropriate value.

(Example) Hereinafter, an example is described based on drawings.

FIG. 2 is an overall system diagram of one embodiment of the present invention. In this embodiment, the constant-speed traveling device for a vehicle includes an actuator 3 for opening and closing the throttle valve 1 of the engine via an accelerator wire 2 and a control unit 4 for controlling the same. Then, a vehicle speed sensor is provided in the speedometer 5 of the vehicle, and a vehicle speed signal is input to the control unit 4. The control unit 4 receives command signals in various modes from a command switch (not shown), and also receives a brake signal, an inhibitor signal, and the like.

Here, the command switch sets a resume switch for returning to constant speed running after canceling, a coast switch for decelerating during constant speed running, a main switch as a power switch, and a speed for constant speed running. It consists of a set switch for instructing acceleration during constant speed running. The actuator 3 is composed of a motor and an electromagnetic clutch.

When the main switch is turned on and the set switch is turned on in a predetermined vehicle speed range (for example, 40 to 100 km / h) while the vehicle is running with a normal accelerator operation, the vehicle speed at that time is stored in the control unit 4 and the estimated vehicle speed is simultaneously obtained. Under the control, the throttle valve 1 is driven in the opening direction. When the vehicle speed reaches the target vehicle speed set in the memory, the PI
Move to D control.

During traveling at a constant speed, the control unit 4 performs a comparison operation between the actual vehicle speed detected by the vehicle speed sensor and the target vehicle speed. When the vehicle speed is lower than the target value, the control unit 4 operates the actuator 3 in the forward direction to activate the throttle valve 1. When the vehicle speed is high, the actuator 3 is operated in the reverse direction to drive the throttle valve 1 to the closing side, and the constant speed traveling is maintained by repeating this operation.

Also, when the set switch is turned on during constant speed running,
The throttle valve 1 is driven to the open side to increase the vehicle speed, and the vehicle shifts to a constant speed running state in which the vehicle speed when the set switch is turned off is set as a target value. When the coast switch is turned on, the throttle valve 1 is driven to the closed side to reduce the vehicle speed, and the vehicle shifts to a constant speed running state in which the vehicle speed at the time when the coast switch is turned off is a target value.

When a brake signal or an inhibitor signal is input during traveling at a constant speed, a cancel mode is set, the electromagnetic clutch in the actuator 3 is turned off, and the accelerator wire 2 is completely in a normal accelerator operation state. However, the vehicle speed before cancellation is memorized, and after that, if the resume switch is turned on while the vehicle speed is kept at about 40 km / h or more by accelerator operation, the vehicle will return to the constant speed running state with the set vehicle speed before cancellation again Return.

The control unit 4 also counts the sign change of the acceleration, and increases the control gain by a fixed value when the number of changes in the acceleration sign within a certain time period is smaller than a predetermined number, and increases the control gain when the number exceeds the predetermined number. Learn by reducing the value by a certain value.

FIG. 3 shows data showing the salinity characteristics of the vehicle speed when the vehicle shifts from a flat road to a steep slope or the like during traveling at a constant speed. FIG. 3 (a) shows the case of the conventional device, and FIG. FIG. 7B shows a state in which the control gain has become smaller than the required value due to a significant deterioration or the like, and FIG. 10B shows the case of the above embodiment of the present invention. In the case of the conventional device, the vehicle speed decreases due to an increase in load when the vehicle is on a steep slope, and thereafter gradually returns to the target vehicle speed. However, since the gain is small, the time required to return to the target vehicle speed is long. In contrast, in the case of the above embodiment, the control gain is gradually adjusted to an appropriate value by learning as shown in FIG.

Next, the control of the above embodiment will be specifically described with reference to the flowchart shown in FIG. S indicates each step.

To start, first check in S1 if the set switch is on. If the answer is no, the procedure returns to the original state. If the answer is yes, the procedure goes to S2.

At S2, the vehicle speed V is input, and at S3, the vehicle speed V is stored as the target vehicle speed.

Next, the actual vehicle speed _VA is input in S4. Then, go to S5, and calculates a difference Delta] v _'n of the current vehicle speed difference Delta] v _n and _{(Δv n = V-V A} ) and the previous vehicle speed deviation Delta] v _n-1, then go to S6, the current Vehicle speed deviation Δv _n and vehicle speed deviation Δv _{n-2 two} times before
Then, the difference Δv ″ _n is calculated, and in S7, Δv _n , Δ
Based on v ′ _n and Δv ″ _n , an operation amount Δθ of the actuator is calculated by the following equation.

Δθ = K _T (K _P Δv ′ _n + K _I Δv _n + K _D Δv ″ _n ) where K _P , K _I , and K _D are constants, and K _T is the overall gain.

Then, the flow goes to S8 to operate the actuator by Δθ.

Next, in S9, the sign of the differential value Δv ′ _n−1 of the previous vehicle speed deviation is compared with the sign of the differential value Δv ′ _n of the current vehicle speed deviation, and it is determined in S10 whether the sign has changed between the previous time and the present time. I do.

If there is a sign change, S11
In by adding 1 to T ₀ is the count value of the count, subtracting the timer value T by one to go to S12.

 If the answer is NO in S10, the process directly goes to S12.

Next, in S13, it is determined whether or not the timer value T has become zero. If T = 0, go to S14 and S11
Inputting a count value T ₀ as the number of sign changes.

Next, it is determined whether the T ₀ in step S15 whether the first is greater than the specified value K _1. Then, if the fact that T _0> K _1, S1
Going to 6, the gain K _T is reduced by a constant value ΔK _T.

If T ₀ > K _{1 is} not satisfied, T ₀ is equal to the second specified value K _{2 in} S 17.
It is checked whether it is smaller than (K ₂ <K ₁ ), and if T ₀ <K ₂ , the process goes to S 18 to increase the gain K _T by ΔK _T.

Thereafter, returning the count value T ₀ to zero at S19, to return the timer value T to the initial value 10 in S20, the flow returns to S4.

Also, if NO in S13, that is, if T = 0, and
If No, that is, if T ₀ = 0, the process returns to S4.

In the above embodiment, the control gain K _T is increased or decreased by a constant value ΔK _T according to the number of changes in the acceleration sign. However, the gain K _T may be learned by a weighted average. In this case, K _T is set as follows.

Also, further, the control gain K _T, initially may be so is set smaller than is upcoming value obtained by the actual vehicle test.

Further, the control gain K _T is small when the vehicle speed difference Delta] v _n is small, or may be large when Delta] v _n is large.

(Effect of the Invention) Since the present invention is configured as described above and the control gain is automatically adjusted during traveling, it is not necessary to set a dedicated gain for each vehicle type at the development stage, and development is facilitated. In addition, it is possible to always obtain an appropriate gain and perform constant-speed running control in response to changes in the total weight of the vehicle and deterioration over time of the engine performance.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of the present invention, FIG. 2 is an overall system diagram of one embodiment of the present invention, FIG. 3 is a characteristic diagram showing control characteristics of the embodiment in comparison with a conventional device, FIG. FIG. 4 is a flowchart for executing the control of the embodiment. 1: Throttle valve, 3: Actuator, 4: Control unit, 5: Speedometer (vehicle speed sensor).

Continuation of front page (72) Inventor Takeshi Yamane 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Naldec Co., Ltd. (56) References JP-A 64-9035 (JP, A) JP-A 60-255534 ( JP, A) JP-A-63-64833 (JP, A) JP-A-2-92742 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 31/00 F02D 29/02 301

Claims (1)

(57) [Claims] 1. An engine output adjusting means for adjusting an output of an engine, an actuator for driving the engine output adjusting means, a target vehicle speed setting means for setting a target vehicle speed of a vehicle driven by the engine, and an actual vehicle speed. Vehicle speed detection means for detecting a vehicle speed and a constant speed traveling control means for controlling the actuator based on a deviation between the detected vehicle speed and the target vehicle speed to maintain the vehicle in a constant speed traveling state. In the device, acceleration code detection means for detecting an acceleration code from a vehicle speed change state during constant-speed running control, and receiving the output of the acceleration code detection means, the number of changes of the acceleration code within a predetermined time is a predetermined number of times. A constant speed traveling device for a vehicle, further comprising control gain changing means for changing a control gain of the constant speed traveling control means.